That's interesting, it says "Vectoring Active". That's possibly related to why the 2850 isn't able to sync, its chipset predates vectoring.

Since you're seeing dropouts with your line, please try the "Vigor 2860 Series Vector4 (579F17) Firmware 3.8.9.3" firmware instead of the regular BT firmware to test.

If that still doesn't help, please get in touch with support, I think vectoring on a UK Openreach line is new / rare at the moment.

Hi

just installed that firmware. i will let you know how i get on thank you!

Dave

18 hours uptime with this firm so maybe that was the problem. the latest version was causing the dropouts because of the vectoring?

What is vectoring for by the way?

Thanks for all your help
Dave

That's great news, but also interesting that it required the different modem code for stability.

Vectoring is a pretty complex xDSL technology that's like noise reduction / error correction between bundled VDSL lines. So the EM interference / crosstalk caused by all of the other cables in your local Openreach VDSL cabinet, doesn't drop the speeds of your VDSL connection.
It's been a problem for a while, where once a VDSL cabinet is fully subscribed, the speeds drop for all users because of the crosstalk.

It's taken a long time to come into use because the VDSL cabinet needs to support it, and every single VDSL modem connected to it has to support vectoring, for vectoring to be effective.